Dear Iriowen,
To be candid, you were likely not successful, otherwise you should have heard from them either way.
My thoughts are that, you were not checking your junk emails (i.e Spam folder) before emptying them, most regrets letters sent out by Shell automatcally went into that email folder.
I willl advice that you forget about the past and move on with life, there are better and wonderful opps out there. You could still re-apply when vacancies exist in the future, until then continue to strive for others.
Kind regards!